Susan Collins faces toughest Senate race as Maine becomes battleground

Susan Collins has spent nearly three decades turning Maine into her political base, and now that durability is colliding with the most precarious Senate race of her career. The Republican incumbent is the longest-serving Republican woman in Senate history, yet she is also the party’s most vulnerable incumbent this year, a paradox that has made Maine one of the sharpest battlegrounds in the country.

Collins first entered the Senate in 1996, when she succeeded Bill Cohen. She was reelected in 2002, 2008, 2014 and 2020, and in 2020 she became the first-ever Republican woman to win a fifth term. She is also the first popularly elected U.S. senator from Maine to reach a fifth term, a record that speaks to both her resilience and the state’s willingness to split its ticket.

Her seniority still gives her real leverage in Washington. Collins is the seventh-most senior member of the Senate and the most senior Republican woman, and she recently became chair of the Senate Appropriations Committee, which oversees discretionary federal spending. That post gives Maine an important voice in budget fights and federal spending decisions, and a Collins defeat would almost certainly change the state’s standing in those negotiations.

That is why the 2026 race has drawn such intense national attention. The general election is set for November 3, 2026, and Maine will once again use ranked-choice voting. Democrats have lined up Graham Platner, who won the party’s primary, after Gov. Janet Mills suspended her campaign on April 30, 2026. Mills’ exit sharpened the race rather than calming it, leaving Platner to carry the Democratic challenge in a contest already defined by volatility.

Polling in spring 2026 has underscored Collins’ vulnerability. Surveys from Emerson College Polling and the University of New Hampshire Survey Center showed her in a close race with Platner, and at times trailing him. Earlier matchups against Mills were also tight, reinforcing the sense that Collins is no longer running from a position of easy incumbency.

Her official biography still emphasizes a record of discipline and institutional weight: Collins has never missed a vote in 19 years in office and has cast more than 6,000 votes in a row. That combination of reliability at home and exposure in a polarized national environment is what makes her such a lasting figure in Maine politics. She remains central to the state’s political identity precisely because she is both its Republican institution and its most endangered incumbent.